/*
 * This file is part of the GROMACS molecular simulation package.
 *
 * Copyright (c) 1991-2000, University of Groningen, The Netherlands.
 * Copyright (c) 2001-2004, The GROMACS development team,
 * check out http://www.gromacs.org for more information.
 * Copyright (c) 2012,2013, by the GROMACS development team, led by
 * David van der Spoel, Berk Hess, Erik Lindahl, and including many
 * others, as listed in the AUTHORS file in the top-level source
 * directory and at http://www.gromacs.org.
 *
 * GROMACS is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1
 * of the License, or (at your option) any later version.
 *
 * GROMACS is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with GROMACS; if not, see
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 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA.
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 */

#ifndef _gmx_system_xdr_h
#define _gmx_system_xdr_h

#include <limits.h>
#include <stdio.h>
#include <stdlib.h>


/*
 * This header file is ONLY used on windows systems, since these do
 * not include the XDR routines present on a unix machine. It will
 * most probably work on other platforms too, but make sure you
 * test that the xtc files produced are ok before using it.
 *
 * This header file contains Gromacs versions of the definitions for
 * Sun External Data Representation (XDR) headers and routines.
 *
 * On most UNIX systems this is already present as part of your
 * system libraries, but since we want to make Gromacs portable to
 * platforms like Microsoft Windows we have created a private version
 * of the necessary routines and distribute them with the Gromacs source.
 *
 * Although the rest of Gromacs is LGPL, you can copy and use the XDR
 * routines in any way you want as long as you obey Sun's license:
 *
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 *
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 *
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 *
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 *
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */

#ifdef __cplusplus
extern "C" {
#endif

/*
 * Xdr operations.  XDR_ENCODE causes the type to be encoded into the
 * stream.  XDR_DECODE causes the type to be extracted from the stream.
 * XDR_FREE can be used to release the space allocated by an
 * XDR_DECODE request.
 */

/* We already have a boolean type in Gromacs, but the XDR library
 * one has a slightly different name (the calls should be identical).
 */
typedef int bool_t;

/*
 * Aninteger type that is 32 bits wide. Check if int,
 * long or short is 32 bits and die if none of them is :-)
 */
#if (INT_MAX == 2147483647)
typedef int xdr_int32_t;
typedef unsigned int xdr_uint32_t;
#elif (LONG_MAX == 2147483647L)
typedef long xdr_int32_t;
typedef unsigned long xdr_uint32_t;
#elif (SHRT_MAX == 2147483647)
typedef short xdr_int32_t;
typedef unsigned short xdr_uint32_t;
#else
#  error ERROR: No 32 bit wide integer type found!
#endif

enum xdr_op {
    XDR_ENCODE = 0,
    XDR_DECODE = 1,
    XDR_FREE   = 2
};

#ifndef FALSE
#      define  FALSE   (0)
#endif
#ifndef TRUE
#      define  TRUE    (1)
#endif


#define BYTES_PER_XDR_UNIT  (4)
/* Macro to round up to units of 4. */
#define XDR_RNDUP(x)  (((x) + BYTES_PER_XDR_UNIT - 1) & ~(BYTES_PER_XDR_UNIT - 1))


/*
 * The XDR handle.
 * Contains operation which is being applied to the stream,
 * an operations vector for the particular implementation (e.g. see xdr_mem.c),
 * and two private fields for the use of the particular implementation.
 */
typedef struct XDR XDR;
struct XDR
{
    enum xdr_op x_op;       /* operation; fast additional param */
    struct xdr_ops
    {
        bool_t       (*x_getbytes) (XDR *__xdrs, char *__addr, unsigned int __len);
        /* get some bytes from " */
        bool_t       (*x_putbytes) (XDR *__xdrs, char *__addr, unsigned int __len);
        /* put some bytes to " */
        unsigned int (*x_getpostn) (XDR *__xdrs);
        /* returns bytes off from beginning */
        bool_t       (*x_setpostn) (XDR *__xdrs, unsigned int __pos);
        /* lets you reposition the stream */
        xdr_int32_t *(*x_inline) (XDR *__xdrs, int __len);
        /* buf quick ptr to buffered data */
        void         (*x_destroy) (XDR *__xdrs);
        /* free privates of this xdr_stream */
        bool_t       (*x_getint32) (XDR *__xdrs, xdr_int32_t *__ip);
        /* get a int from underlying stream */
        bool_t       (*x_putint32) (XDR *__xdrs, xdr_int32_t *__ip);
        /* put a int to " */
        bool_t       (*x_getuint32) (XDR *__xdrs, xdr_uint32_t *__ip);
        /* get a unsigned int from underlying stream */
        bool_t       (*x_putuint32) (XDR *__xdrs, xdr_uint32_t *__ip);
        /* put a int to " */
    }
    *x_ops;
    char *x_public;     /* users' data */
    char *x_private;    /* pointer to private data */
    char *x_base;       /* private used for position info */
    int   x_handy;      /* extra private word */
};

/*
 * A xdrproc_t exists for each data type which is to be encoded or decoded.
 *
 * The second argument to the xdrproc_t is a pointer to an opaque pointer.
 * The opaque pointer generally points to a structure of the data type
 * to be decoded.  If this pointer is 0, then the type routines should
 * allocate dynamic storage of the appropriate size and return it.
 */

typedef bool_t (*xdrproc_t) (XDR *, void *, ...);

/*
 * Operations defined on a XDR handle
 *
 * XDR          *xdrs;
 * xdr_int32_t  *int32p;
 * long         *longp;
 * char         *addr;
 * unsigned int  len;
 * unsigned int  pos;
 */


#define xdr_getint32(xdrs, int32p)                      \
    (*(xdrs)->x_ops->x_getint32)(xdrs, int32p)

#define xdr_putint32(xdrs, int32p)                      \
    (*(xdrs)->x_ops->x_putint32)(xdrs, int32p)

#define xdr_getuint32(xdrs, uint32p)                      \
    (*(xdrs)->x_ops->x_getuint32)(xdrs, uint32p)

#define xdr_putuint32(xdrs, uint32p)                      \
    (*(xdrs)->x_ops->x_putuint32)(xdrs, uint32p)

#define xdr_getbytes(xdrs, addr, len)           \
    (*(xdrs)->x_ops->x_getbytes)(xdrs, addr, len)

#define xdr_putbytes(xdrs, addr, len)           \
    (*(xdrs)->x_ops->x_putbytes)(xdrs, addr, len)

#define xdr_getpos(xdrs)                \
    (*(xdrs)->x_ops->x_getpostn)(xdrs)

#define xdr_setpos(xdrs, pos)               \
    (*(xdrs)->x_ops->x_setpostn)(xdrs, pos)

#define xdr_inline(xdrs, len)               \
    (*(xdrs)->x_ops->x_inline)(xdrs, len)

#define xdr_destroy(xdrs)                   \
    do {                            \
        if ((xdrs)->x_ops->x_destroy) {           \
            (*(xdrs)->x_ops->x_destroy)(xdrs); }  \
    } while (0)


bool_t xdr_int (XDR *__xdrs, int *__ip);
bool_t xdr_u_int (XDR *__xdrs, unsigned int *__ip);
bool_t xdr_short (XDR *__xdrs, short *__ip);
bool_t xdr_u_short (XDR *__xdrs, unsigned short *__ip);
bool_t xdr_bool (XDR *__xdrs, int *__bp);
bool_t xdr_opaque (XDR *__xdrs, char *__cp, unsigned int __cnt);
bool_t xdr_string (XDR *__xdrs, char **__cpp, unsigned int __maxsize);
bool_t xdr_char (XDR *__xdrs, char *__cp);
bool_t xdr_u_char (XDR *__xdrs, unsigned char *__cp);
bool_t xdr_vector (XDR *__xdrs, char *__basep, unsigned int __nelem,
                   unsigned int __elemsize, xdrproc_t __xdr_elem);
bool_t xdr_float (XDR *__xdrs, float *__fp);
bool_t xdr_double (XDR *__xdrs, double *__dp);
void xdrstdio_create (XDR *__xdrs, FILE *__file, enum xdr_op __xop);

/* free memory buffers for xdr */
void xdr_free (xdrproc_t __proc, char *__objp);

#ifdef __cplusplus
}
#endif

#endif /* _gmx_system_xdr_h */
